JP3116424B2 - Door-to-door receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a door-to-door receiver for a disaster management radio system. The emergency radio system is composed of a fixed system, a mobile system, and a telemeter system, or a combination thereof.

[0002] The fixed system is 60 M from the master station installed in the local government.
A system that transmits information to residents through a wireless transmission channel in the Hz band.A system that broadcasts a wide area using speakers from outdoor slave stations installed in various places in the local government, and a separate receiver installed in each home. There is a method of broadcasting in units.

Here, for example, when an emergency broadcast is automatically recorded / reproduced by a door-to-door receiver, since the receiver does not have a function of recording / reproducing, the recording / reproducing device and the recording device are automatically activated. An additional circuit was required to perform the operation.

[0004] Therefore, a simple recording / reproducing portion is incorporated in a door-to-door receiver to automatically record a necessary broadcast, and to display the presence or absence of the recording so that the above-mentioned broadcast is not overlooked. is necessary.

[0005]

2. Description of the Related Art FIG. 4 is a block diagram of a conventional door-to-door receiver. Hereinafter, the operation of FIG. 4 will be described.

First, when a master station transmits information to a slave station, for example, a paging signal, a group paging signal, a door-to-door paging signal, a broadcast start signal, a broadcast end signal, etc. (these signals are collectively specified signals) Is transmitted.

All the specific signals are digital signals having different patterns. The master station performs subcarrier MSK modulation, arranges the audio signal for broadcasting transmission information in a predetermined format, and FM modulates the carrier. Also, as the type of broadcast, for example, there are emergency, office communication, and the like.

The high-frequency amplifier 111 receives an FM modulated wave (with a frequency of 50 to 70 MHz) from a master station input via an antenna.
, Which has a designated frequency) and amplifies the amplified signal to the first mixer 112.

Here, the first local oscillator 121 outputs the first
Since a local oscillation signal is also added, the received FM modulated wave
The frequency is converted to an FM modulated wave of 0.7 MHz and applied to the second mixer 114 via the first intermediate frequency amplifier 113.

Since the second mixer receives the second local oscillation signal from the second local oscillator 122, the frequency is converted to an FM modulated wave of 455 KHz, and then the frequency is discriminated through an amplitude limiter 116. Add to 117. The frequency discriminator demodulates the input FM modulated wave, extracts a frequency discrimination signal, and applies the signal to the high-pass filter 21 and the low-frequency amplifier 118.

The high-pass filter extracts a noise component having a frequency equal to or higher than a predetermined frequency in the frequency discrimination signal, amplifies and detects the noise component with the noise amplifier 22, and applies, for example, an L-level noise amplifier output to the gate 26. The L level indicates that the input level of the receiving unit is equal to or higher than a specified level.

On the other hand, the frequency discrimination signal passed through the low frequency amplifier 118 is applied to the MSK demodulator 23 and the switch 119. Now, the MSK demodulator converts the frequency discrimination signal,
The signal is demodulated and a specific signal is extracted and added to the CPU 24.

When the CPU compares the input specific signal pattern with the internal specific signal pattern and detects that the calling signal following the transmission start signal includes its own station, the CPU determines a predetermined signal. The detection output in the state of being turned on is sent to the gate 26.

The gate 26 has the output of the noise amplifier at L level,
When a detection output in a predetermined state is input from the CPU,
Since the switch 119 is turned on and a start signal is sent to the adapter 31, the adapter starts the tape recorder 32.

Since the low-frequency amplifier 120 includes a filter (not shown) that passes only the audio signal, the input audio signal is amplified to drive the speaker SPK and input to the tape recorder 32. Recorded.

When the CPU 24 detects that the end-of-broadcast signal has been input, the CPU 24 sends a detection output in a predetermined state to the gate 26. This causes the gate 26 to switch
Since the 119 is turned off and the start signal is turned off, the tape recorder stops recording.

[0017]

As described above, since the door-to-door receiver does not have a recording / reproducing function, even if there is an emergency broadcast from the master station, it may be missed on the receiving side. Requires that an adapter having a function of transmitting an automatic recording / stop signal and a recording / reproducing device be provided externally.

Further, since there is no indication on the recording / reproducing apparatus whether or not a broadcast is recorded, there is a problem that the presence or absence of the recording cannot be recognized unless the broadcast is reproduced. An object of the present invention is to provide a door-to-door receiver with a built-in simple recording / playback part to automatically record necessary broadcasts, to display the presence / absence of recording, and to prevent the above-mentioned broadcasts from being overlooked. .

[0019]

FIG. 1 is a block diagram showing the principle of the present invention. In the figure, reference numeral 1 denotes a receiving / demodulating portion for extracting a specific signal such as a group call signal or a broadcast start signal and an audio signal from a received signal, and a receiving unit including a speaker driven by the audio signal, and 2 denotes a pattern of an input specific signal. And analyze
The signal receiving unit sends a recording start signal when the analysis result matches the first pattern set in advance, and sends a recording stop signal when the analysis result matches the second pattern.

Reference numeral 4 denotes a recording / reproducing portion which encodes and stores an input audio signal, decodes the stored encoded audio signal and reproduces the audio signal. Reference numeral 5 denotes a playback switch. When the recording start signal is input, the recording / playback part is started, and when the recording stop signal is input, the recording operation of the recording / playback part is stopped. A recording display signal indicating that recording has been completed is transmitted using the input of the start signal and the recording stop signal, and when the reproduction switch is turned on, the recording / reproduction portion is reproduced. This is a control unit having a function of switching from a reproduction operation to a recording operation when a signal is input.

The recording / reproducing part and the control part are built in a door-to-door receiver.

[0022]

According to the present invention, the recording / reproducing part and the control part are built in the door-to-door receiver, and the signal detecting part detects the specific signal from the master station in a first pattern (for example, simultaneous broadcast). When it is detected that the call signal is the same as the call signal or the group call signal pattern including the own station, a recording start signal is sent to the recording / playback part via the control part to automatically record.

That is, as a result of analyzing the specific signal transmitted from the master station, when the signal receiving section detects that the signal indicates the first pattern set in advance, the signal receiving section transmits the recording start signal to the control section. Then, the control section activates the recording / playback section.

The recording / reproducing portion is composed of a voice recording / reproducing MOS LSI having a high-efficiency voice encoding / decoding function, for example. Some of the converted audio signals are stored in memory (RAM
) And the rest is decoded to drive the speaker.

However, when the analyzed specific signal is detected to be the same as the second pattern set in advance (for example, the pattern of the broadcast end signal), a recording stop signal is transmitted to the control unit. Therefore, the control section stops the recording operation of the recording / playback section.

At this time, the control unit sends out a recording display signal indicating that recording has been completed by using the sending of the recording start signal and the recording stop signal. Next, by pressing a switch SW provided in the control section, a reproduction start signal is transmitted to the recording / reproduction section.
Thereby, the encoded audio signal is read from the memory,
The audio signal is reproduced by being decoded in the recording / reproducing part, and the speaker is driven.

When a recording start signal is input to the control part during reproduction, the recording / reproduction part is switched from the reproduction operation to the recording operation, and the broadcast content from the master station is automatically recorded. That is, a simple recording / reproducing portion is incorporated in a door-to-door receiver to automatically record a necessary broadcast, and the presence / absence of the recording is displayed so that the above-mentioned broadcast is not missed.

[0028]

FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a diagram showing an example of a control circuit in FIG. Here, although FIG. 3 partially uses a relay to simplify the explanation of the operation, it goes without saying that it can be constituted by a logic element.

Also, a low frequency input part 41, adaptive delta modulation
(ADM) analysis / synthesis circuit 42, low-frequency output part 4
5, RAM interface 43 and RAM 44 are components of the recording / reproducing portion 4, and the control circuit 51 and switch SW are components of the control portion 5.

The same reference numerals indicate the same objects throughout the drawings. Hereinafter, the operation of FIG. 2 will be described with reference to FIG. 3, but since the operations of the receiving unit 1 and the signal receiving unit 2 have been described in detail above, they will be briefly described. The operation of the control unit will be described in detail.

First, the signal receiving unit 2 analyzes the call signal and the broadcast type signal transmitted following the broadcast start signal from the master station, and as a result, the call signal is a general call signal and a signal indicating an emergency broadcast. Has been detected to match the pattern
The CPU 24 sends an H level recording start signal to the control circuit 51 via the I / O 25 and the gate 26.

Therefore, the rise detecting portion 511 of the control circuit is provided.
Detects the application of the recording start signal and outputs an H-level output, so that the relay R operates and the contacts r ₁ and r ₂ become as shown by dotted lines. This turns on the gate 514,
The clock generation section 513 outputs a clock of a predetermined speed through the analysis / synthesis circuit (ADM) 42 and the selector 515 in a solid line state.
Send to the write side of RAM.

Then, the analysis / synthesis circuit is activated.
The analysis part encodes the audio signal from the reception part using a clock of a predetermined speed, and stores a part in the RAM 44 through the RAM interface 43, and decodes the other part in the synthesis part and outputs a low frequency signal. The unit 45 drives the speaker SPK via the low-frequency power amplifier 120.

The supplied clock is, for example, 8 KH
It has a set speed among z, 16KHz and 32KHz. Also, the storage in RAM is the update of the previously stored one.

The master station sends an end-of-broadcast signal when the broadcast ends. When the CPU of the signal receiving unit detects this signal, the master station sends the recording start signal sent via the I / O and the gate. Cut off.

Therefore, the falling detection section 512 detects that the level of the recording start signal has changed from H to L, indicates that recording has been completed, and resets the rising detection section to return to the initial state. , Reset relay R. As a result, the contacts r ₁ and r ₂ are in the solid line state, the AND gate is in the off state, the supply of the clock is stopped, and the operation of the recording / playback part is stopped.

Next, after the end of the recording process, when the owner of the door-to-door receiver turns on the reproduction switch SW according to the recorded indication, the relay S operates and the contacts s _{1 to} s ₄ are set to the dotted lines. Therefore, the relay is self-held, the AND gate is turned on, the selector 515 is in the dotted line, and the falling detection portion is reset.

Therefore, the clock is used for the analysis / synthesis circuit and the RAM.
And the recording indication disappears. The encoded audio signal read from the RAM is then reproduced by the synthesizer of the analysis / synthesis circuit via the RAM interface, and the speaker is driven via the low frequency output unit 45 and the low frequency power amplifier. I do.

When a recording start signal is input to the control circuit during the reproduction operation, the rising detection section detects this start signal and drives the relay R, so that the reproduction switch SW is turned off and the reproduction operation is interrupted. At the same time, the selector returns to the solid line state and the clock is supplied to the analysis / synthesis circuit and the write side of the RAM, so that the broadcast from the master station can be written to the RAM.

[0040]

As described above in detail, according to the present invention, a simple recording / reproducing portion is incorporated in a door-to-door receiver to automatically record a required broadcast, and the presence / absence of recording is displayed. There is an effect that it is possible to prevent a missed broadcast from being heard.

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a block diagram of an embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of a control circuit in FIG. 2;

FIG. 4 is a block diagram of a conventional door-to-door receiver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receiving part 2 Signal receiving part 4 Recording / playback part 5 Control part

Claims (1)

(57) [Claims] 1. A receiver for extracting a specific signal such as a group call signal or a broadcast type signal and an audio signal from a received signal.
Receiving unit comprising a speaker driven by the demodulation section and the voice signal
When analyzes the pattern of a particular signal input, the analysis results were set in advance, when matching the first pattern sends the recording start signal, the recording stop signal when matching a second pattern A signal receiving unit to be transmitted, and a recording / reproducing unit that encodes and stores an input audio signal, decodes the stored encoded audio signal, and reproduces the audio signal.
Min, a reproduction switch, when該録sound activation signal is inputted to the recording start該録sound-reproduction part, together when該録sound stop signal is input stops the recording operation of the recording and playback section,該録sound Using the input of the start signal and the recording stop signal, a recording display signal indicating that recording has been completed is sent out.
The reproduction section is reproducing operation, when the input該録sound activation signal during the reproducing operation, door-to-door receiver characterized by having a minute control unit has a function to switch the recording operation from the reproduction operation.